Development of real-road CO2 emission factors for diesel light-duty vehicles across diverse driving conditions

The transportation sector is a major contributor to global CO2 emissions, necessitating effective strategies to mitigate greenhouse gas emissions. This study develops a robust methodology for estimating CO2 emissions from diesel light-duty vehicles (LDVs) based on real-road driving data. By analyzing the relationships between CO2 emissions and key vehicle parameters, including curb weight, engine displacement, engine rated power, and driving resistance, CO2 emission factors were derived for diverse driving conditions: Urban (traffic), Urban (normal), Rural, and Motorway. Using multiple linear regression, the study incorporates highly correlated parameters to create practical and accurate emission factor models. Validation was conducted using two vehicles with commonly observed specifications, and independent test data showed prediction errors ranging from 1 % to 5 %, demonstrating the model's reliability in reflecting real-world conditions. This study provides emission factors tailored to real-road conditions, enabling precise CO2 estimation under diverse driving scenarios and enhancing the understanding of vehicle emissions in practical applications.